Both the ones I found were less than $100, though there are lot so fthem that are between $150 and $20025

I vote for looking in the Yellow Pages to find a restaurant-supply place, or a Janitorial-supply place, or a hospital-supply place. You'll want to enquire whether you'll need a resale number; some places only sell wholesale. (some of *those* places have offered to sell me stuff at the wholesale price if I paid cash)

Check out some of the taller TV or cookware-type carts. I put one together with the shelves installed upside down so that each of the three shelves had a nice 1" rim all the way around, for my husband's hobbyist work.

How heavy duty? They make carts for libraries that will hold up to 2000lbs! (Of course they cost about $600, but that's pretty dang heavy duty!) They call them "book trucks" in the library world - they have ones at various price points that hold anywhere form 500lbs up to the 2000lb 'monster' book truck